Draftsman&#39;s triangle having a parallel line spacer



Dec. 29, 1953 L. G. PERETTI 2,563,939.

DRAFTSMANS TRIANGLE HAVING A PARALLEL LINE SPACER Filed Oct. 19, 1951 INVENTOR 6 77L) I *0 ATTORNEYS Patented Dec. 29,1953

DRAFTSMANS TRIANGLE HAVING A PARALLEL LINE SPACER.

Leonard G. Peretti, Chicago, Ill.

Application October 19, 1951, Seri'al No. 252,158

1 Claim. 1

This invention relates to drafting instruments. More particularly, the invention has reference to a draftsmans triangle, so constructed as to have embodied therein a parallel line spacing means.

In drafting operations, or for that matter in many other types of drawing, the necessity of making a series of equidistantly spaced. parallel lines frequently arises. In this connection, measuring off of the distance between each pair of adjacent parallel lines is a laborious and timeconsuming operation, and is avoided wherever possible. On the other hand, visual determination of the spaces between adjacent parallel lines to be drawn results in inaccuracies.

Accordingly, it is the main object of the pres ent invention to provide a ,draftsmans triangle having a parallel line spacing means embodied therein, said means being so formed as to permit a series of parallel lines to be drawn, in a minimum time and with maximum facility.

Another important object is to provide a drafting instrument of the character described which has a parallel line spacer incorporated therein in such a manner that the spacer will not interfere with ordinary use of the instrument.

Still another important object is to provide a draftsmans triangle as stated wherein the parallel line spacing means is so designed as to be capable of incorporation in the triangle at a minimum of cost.

Yet another important object is to provide a draftsmans triangle as described wherein the parallel line spacing means is adjustable to predetermine, within wide limits, the distance which is to occur between the severa1 parallel lines.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawing, in which like referencecharacters designate like parts throughout the several views, and wherein:

Figure 1' is a plan view of a drafting board, showing the draftsmans triangle formed in acoordance with the present invention, as it appears when in use;

Figure 2 is an enlarged plan View of the triangle;

Figure 3 is a fragmentary perspective view of the triangle and of the parallel line spacing means embodied therein;

Figure 4 is a longitudinal sectional view through the spacing means, on a scale enlarged still further, taken substantially on line 4-4 of Figure 2; and

Figure 5 is a transverse sectional View through the spacing means, taken on line 5-5 of Figure 2 and drawn on the scale of Figure 4.

The draftsmans triangle formed in accordance with the present invention has been generally designated lt, and is formed with a rectangular opening it having perpendicularly related sides that are parallel to the respective perpendicularly related legs of the triangle.

Formed upon and extending from end to end of opposite sides of the opening 12 are tongues It, disposed medially between the top and bottom faces of the triangular. body it, as may be readilynoted from Figure 4.

The tongues it provide guides for slidable movement of a flat plate I 6 adapted to be shifted longitudinally of the rectangular opening 12. The plate it is formed to a thickness corresponding to that of the triangular body iii, andas may be noted from Figure 5, the plate It is integrally formed with outwardly extended longitudinal tongues l8, said tongues it being contiguous to the bottom face of the plate l6 and underlying the guide tongues M of the triangular body It.

At its opposite sides, the rectangular plate i5 is formed with longitudinal recesses 26, contiguous to the top face thereof, said recesses being adapted to receive filler pieces 22, that are bonded along opposite sides to the Walls of the recesses. The filler pieces project beyond the re-, cesses, to an extent corresponding to the projection of the tongues it (Figure 5). Thus, there are defined within opposite sides of the rectangular plate i6 guide grooves receiving the guide tongues M.

The plate It is freely slidable upon the guide tongues It, sliding from end to end of the opening i2.

Formed in the rectangular plate 16, and dis posed medially between the opposite sides of the plate, is a longitudinal slot 2 1, closed at opposite ends, said slot receiving a vertically positioned stem 26. The stem 26 (Figures 4 and 5) is threaded at its upper end, said upper end projecting beyond the top face of the rectangular plate it and being threadedly engaged with a knob 28.

At its lower end, the stem 28 is provided with an enlargement 3t embedded in an extension member 32, that is recessed in a complementarily formed seat 3 3, that is provided in the bottom face of the plate It.

The extension member 32 is slidable relative to the rectangular plate It, and is provided with a series of graduations 36, said graduations in the present instance being inches and fractions thereof.

The extension member 32 is adjusted so as to project beyond the rectangular plate 16 a selected distance, the end wall of the rectangular plate being brought into register with a selected graduation. This causes the spacer unit, said unit comprising the plate [6 and the extension member 32, to be extended as to the overall length thereof, to bring its length up to a predetermined ratio relative to the length of the opening l2 in which said unit is slidably mounted. In other words, the overall length of the spacer unit, when subtracted from the length of the opening I2, will give the space which is to occur between each pair of parallel lines to be drawn.

In Figure 1, I have illustrated a T square 38, that is applied to a conventional drafting board 40 on which a sheet of drafting paper 42 is provided. Parallel lines 44 are to be drawn on the sheet of paper.

'The triangle is applied to the T square straight edge in the usual manner, after the spacer unit has been adjusted to a selected length. The triangle is held against the board, and one line 44 is drawn.

The spacer unit is then held against movement, and the triangle is shifted along the straight edge relative to the now stationary spacer unit, until the free end of the extension member is engaged by the adjacent end of the opening l2, in the manner shown at the right in Figure 1.

A second line 4 1 is now drawn, after which the triangle is held stationary while the spacer unit is moved until it again abuts against the opposite end of the opening 52. The unit is then held stationary once again, and, the triangle shifted to the limit allowed by the spacer unit. Another line is drawn, and succeeding lines are drawn in the same manner.

It will be readily apparent that with considerable ease, one can acquire dexterity in the manipulation of the device, so as to make the relative movements between the triangular body it and the spacer unit unconsciously during the drawing of a series of parallel lines.

It is also believed worthwhile to note that the device is one which does not interfere with ordinary use of the triangle, since it does not project beyond any side of the triangle, or below the bottom face of the triangle.

Still further, the device is capable of incorporation in triangles without increasing the cost thereof materially, the increased cost being more than offset by the benefits to be obtained through use of the device.

It is believed clear that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles of operation and the means presently devised to carry out said principles, it being considered that the invention comprehends any minor changes in construction that may be permitted within the scope of the appended claim.

What is claimed is:

A drafting instrument comprising a draftsmans triangle having a rectangular opening formed with perpendicularly related sides respectively parallel to the perpendicularly related sides of said triangle, said opening having guide tongues extending the length thereof, along the opposite side edges of the opening; a rectangular plate mounted in the opening and having its top and bottom surfaces flush with the top and bottom surfaces of the triangle, said plate having a wide, shallow recess formed in its underside, said recess extending the length of the plate, the plate having longitudinal recesses of right angled cross section opening on one of said surfaces thereof and extending along the opposite sides of the plates; filler pieces fixedly mounted in the secondnamed recesses; longitudinal guide tongue members integral with the respective sides of the plate contiguous to the other surface of the plate, the filler pieces and the tongue members of the plate projecting outwardly from the plate to the same extend and being spaced apart to define guide grooves at opposite sides of the plate slidably interengaged with the guide tongues; a graduated extension member disposed within said recess, said extension member having a bottom surface flush with the bottom surface of the rectangular plate, one end of the extension member projecting beyond one end of the plate; and means engaging the plate and extension member against relative movement from selected positions to which the extension member is slidabiy adjusted relative to the plate, said means comprising a stem projecting upwardly from the extension member and embedded in the extension member, said plate having an elongated, closed slot through which the stem is extended, said means further including a knob threadedly engaged with the stem for tightening of said knob against the upper surface of the plate, thereby to rigidly interengage the plate and extension member in said selected positions of adjustment of the extension member, said plate and extension member constituting a spacer unit slidable from end to end of the rectangular opening of the triangle and adjustable as to its overall length, the difierence between the overall length of the spacer unit and the length of the triangle opening determining the distance the triangle may be moved relative to the spacer unit, thus to permit the drawing of a series of parallel, equidistant, straight lines first by moving the triangle while the spacer unit is held stationary, and then by moving the spacer unit while the triangle is held stationary.

LEONARD G. PER-ETTI.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 951,719 Baum Mar. 8, 1910 2,384,555 Kuhne Sept. 11, 1945 2,410,864 Brown Nov. 12, 1946 2,437,469 Lachmund Mar. 2), 1948 FOREIGN PATENTS Number Country Date 10,199 Austria Dec. 10, 1902 OTHER REFERENCES Publ: Popular Science, June 19 1-8, page 1'76, copy in Div. 66. 

